Blocked bio-based carboxylic acids and their use in thermosetting materials

ABSTRACT

This invention relates to bio-based polyfunctional carboxylic acids reacted with vinyl ether compounds to form liquid vinyl-blocked bio-based polyfunctional carboxylic acids. These liquid vinyl-blocked bio-based polyfunctional carboxylic acids can be mixed with a polyfunctional vegetable oil-based epoxy resin to form a homogeneous curable coating composition. Upon curing at elevated temperature, thermoset coatings are formed which have excellent hardness, solvent resistance, adhesion, and flexibility. The invention also relates to the use of a curable coating composition comprising at least one polyfunctional vegetable oil-based epoxy resin and at least one vinyl-blocked bio-based polyfunctional carboxylic acid, which may be coated onto a substrate and cured thermally. Methods of making the vinyl-blocked bio-based polyfunctional carboxylic acids and curable coating compositions and substrates containing the same are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 to U.S.Provisional Application No. 61/702,082, filed Sep. 17, 2012, which isincorporated herein by reference.

STATEMENT OF GOVERNMENT RIGHTS

This invention was made with government support under Grant NumberEPS0814442 awarded by the National Science Foundation. The governmenthas certain rights in the invention.

FIELD OF THE INVENTION

This invention relates to bio-based polyfunctional carboxylic acidsreacted with vinyl ether compounds to form liquid vinyl-blockedbio-based polyfunctional carboxylic acids. These liquid vinyl-blockedbio-based polyfunctional carboxylic acids can be mixed withpolyfunctional vegetable oil-based epoxy resins to form a homogeneousmixture. Upon curing the homogeneous mixtures at elevated temperature,thermoset coatings are formed which have excellent hardness, solventresistance, adhesion, and flexibility.

The invention also relates to the use of a curable coating compositioncomprising polyfunctional vegetable oil-based epoxy resins andvinyl-blocked bio-based polyfunctional carboxylic acids, which may becoated onto a substrate and cured. The substrate can be any commonsubstrate such as paper, polyester films such as polyethylene andpolypropylene, metals such as aluminum and steel, glass, urethaneelastomers, primed (painted) substrates, and the like.

BACKGROUND OF THE INVENTION

Due to the rising costs and depleting reserves of fossil based oil, itis desired to replace petrochemicals with chemicals based on renewableresources. Most polymers in use today are based on petrochemical derivedmonomers. While there has been some activity to synthesize polymermaterials using bio-based raw materials, in many cases the performanceproperties are inferior to that of the current petrochemical basedtechnology. Thus, there is a need for new polymers based on renewableresources that have excellent performance properties.

Vegetable oil based materials have been used a long time in paints andvarnishes and in alkyd resins. Vegetable oils are derived from the seedsof various plants and are chemically triglycerides of fatty acids. Thatis, vegetable oils consist of three moles of fatty acids esterified withone mole of glycerol. As shown below in Formula I, fatty acids arelinear carboxylic acids having 4 to 28 carbons and may be saturated orethylenically unsaturated.

Different plants produce oils having differing compositions in the fattyacid portion of the oil. Naturally-occurring vegetable oils are bydefinition mixtures of compounds, as are the fatty acids comprisingthem. They are usually either defined by their source (soybean, linseed,etc.) or by their fatty acid composition. A primary variable thatdifferentiates one vegetable oil from another is the number of doublebonds in the fatty acid; however, additional functional groups can bepresent such as hydroxyl groups in castor oil and epoxide groups invernonia oil. Table 1 below identifies the typical fatty acidcomposition for some commonly occurring vegetable oils.

TABLE 1 Fatty Acid Unsaturation Coconut Corn Soybean Safflower SunflowerLinseed Castor Tall Oil FA Tung C₁₂ Lauric 0 44 C₁₄ Myristic 0 18 C₁₆Palmitic 0 11 13 11 8 11 6 2 5 4 C₁₈ Stearic 0 6 4 4 3 6 4 1 3 1 Oleic 17 29 25 13 29 22 7 46 8 Ricinoleic 1 87 Linoleic 2 2 54 51 75 52 16 3 414 Linolenic 3 9 1 2 52 3 3 Eleaosteric 3 80 Iodine 7.5-10.5 103-128120-141 140-150 125-136 155-205 81-91 165-170 160-175 Value

Sucrose, β-D-fructofuranosyl-α-D-glucopyranoside, is a disaccharidehaving eight hydroxyl groups. The combination of sucrose and vegetableoil fatty acids to yield sucrose esters of fatty acids (SEFA) as coatingvehicles was first explored in the 1960s. Bobalek et al., OfficialDigest 453 (1961); Walsh et al., Div. Org. Coatings Plastic Chem. 21:125(1961). However, in these early studies, the maximum degree ofsubstitution (DS) was limited to about 7 of the available 8 hydroxylgroups. The resins do not appear to have been commercialized at thattime. In the early 2000s, Proctor & Gamble (P&G) Chemicals developed anefficient process for industrially manufacturing SEFAs commerciallyunder the brand name SEFOSE with a high DS of at least 7.7 (representinga mixture of sucrose hexa, hepta, and octaesters, with a minimum of 70%by weight octaester) (U.S. Pat. Nos. 6,995,232; 6,620,952; and6,887,947), and introduced them with a focus on marketing to thelubricant and paint industries. Due to their low viscosities (300-400mPa·s), SEFOSE sucrose esters can be used as binders and reactivediluents for air-drying high solids coatings. Formula II displays thepossible molecular structure of a sucrose ester with full substitution.Procter and Gamble has reported a process to prepare highly substitutedvegetable oil esters of sucrose using transesterification of sucrosewith the methyl esters of sucrose (U.S. Pat. No. 6,995,232).

An epoxide group is a three-membered, cyclic ether containing two carbonatoms and one oxygen atom. An epoxide can also be called an oxirane. Asin known in the art, an epoxy group has the structure shown in formulaIII in which R and R′ are organic moieties representing the remainder ofthe compound.

Epoxy resins are materials consisting of one or more epoxide groups. Dueto the strained nature of the oxirane ring, epoxide groups are highlyreactive and can be reacted with nucleophiles such as amines, alcohols,carboxylic acids. Thus, epoxy resins having two or more epoxy groups canbe reacted with compounds having multiple nucleophilic groups to formhighly crosslinked thermoset polymers. Oxiranes can also behomopolymerized. Epoxy resins having two or more epoxy groups can behomopolymerized to form highly crosslinked networks. Crosslinked epoxyresins are used in a large number of applications including coatings,adhesives, and composites, among others. The most commonly used epoxyresins are those made from reacting bisphenol-A with epichlorohydrin toyield difunctional epoxy resins.

Epoxidation of the double bonds in unsaturated vegetable oils results incompounds which incorporate the more reactive epoxy group. Epoxidegroups, or oxirane groups, as discussed, can be synthesized by theoxidation of vinyl groups. Findley et al., J Am. Chem. Soc. 67:412-414(1945), reported a method to convert the ethylenically unsaturatedgroups of triglyceride vegetable oils to epoxy groups, as shown inScheme 1 below. A number of other processes and catalysts have beendeveloped to also achieve epoxidized oils in good yields.

Generally, while there are four techniques that can be employed toproduce epoxides from olefinic molecules (Mungroo et al., J. Am. OilChem. Soc. 85:887 (2008)), the in situ performic/peracetic acid (HCOOHor CH₃COOH) process appears to be the most widely applied method toepoxidize fatty compounds. Scheme 2 displays the reaction mechanism,which consists of a first step of peroxyacid formation and a second stepof double bond epoxidation. Recently, the kinetics of epoxidation ofvegetable oils and the extent of side reactions was studied using anacidic ion exchange resin as catalyst and revealed that the reactionswere first order with respect to the amount of double bonds and thatside reactions were highly suppressed; the conversion of double bonds toepoxides was also high. Petrović et al., Eur. J. Lipid Sci. Technol.104:293 (2002); and Goud et al., Chem. Eng. Sci. 62:4065 (2007). Thecatalyst, Amberlite IR 120, is an acidic ion exchange resin, a copolymerbased on styrene (98 wt %) crosslinked by divinylbenzene (2 wt %). Itsacidity is generated by sulfonic acid groups attached to the polymerskeleton.

Epoxides generated from the epoxidation of double bonds of ethylenicallyunsaturated fatty acids are known as internal epoxides—both carbons ofthe heterocyclic ring are substituted with another carbon. The mostcommonly used epoxy resins are the bisphenol-A diglycidyl ether resins.The epoxy groups on these resins are of the type known as externalepoxides—three of the four substituent groups on the heterocyclic ringare hydrogen atoms. Since internal epoxides are much less reactive thanexternal epoxides in most epoxy curing reactions, the rolestraditionally assigned to epoxidized oils are as stabilizers andplasticizers for halogen-containing polymers (i.e., poly(vinylchloride)) (Karmalm et al., Polym. Degrad. Stab. 94:2275 (2009);Fenollar et al., Eur. Polym. J. 45:2674 (2009); and Bueno-Ferrer et al.,Polym. Degrad. Stab. 95:2207 (2010)), and reactive toughening agents forrigid thermosetting plastics (e.g., phenolic resins). See Miyagawa etal., Polym. Eng. Sci. 45:487 (2005). It has also been shown thatepoxidized vegetable oils can be cured using cationicphotopolymerization of epoxides to form coatings. See Crivello et al.,Chem. Mater. 4:692 (1992); Thames et al., Surf. Coat. Technol. 115:208(1999); Ortiz et al., Polymer 46:1535 (2005).

As noted, epoxidized vegetable oils have found use as plasticizers forpolyvinyl chloride (PVC). When crosslinked directly using the epoxygroups, the resulting products are relatively soft due to the aliphaticnature of the vegetable oil backbone. Epoxidized vegetable oils havebeen further functionalized using acrylation, methacrylation, andhydroxylation.

Epoxy resins based on polyfunctional vegetable oil esters of sucrose canbe crosslinked into high performance thermosets using cyclic anhydrides.See WO 2011/097484, the disclosure of which is incorporated herein byreference.

While the epoxy resin is 100% bio-based, the system uses petrochemicalderived cyclic anhydride crosslinkers, which reduces the overallbio-based content of the thermosets. It is therefore of interest to usecrosslinkers which are also bio-based to form thermosets that are 100%bio-based.

There are a large number of polyfunctional acids available, which areeither currently available from bio-derived processes or for whichbio-based processes are being derived. Some of these acids are shown inTable 2 below. These polyfunctional acids may be used as crosslinkersfor vegetable oil-based epoxy resins, such as, for example, theepoxidized vegetable oil sucrose esters, since the acid groups arereactive with the epoxy groups and the functionality is two or greater.

TABLE 2 Structures of exemplary bio-based acids Acid Name CAS NumberStructure Oxalic 114-62-7

Succinic 110-15-6

Pimelic 111-16-0

Suberic 505-48-6

Azelaic 123-99-9

Sebacic 111-20-6

Brassylic 505-52-2

Citric 77-92-9

Furan Dicarboxylic acid 3238-40-2

Tartaric Acid 526-83-0

However, these acids are crystalline solids with high melting points,and it can be challenging to mix them with the epoxy resin and form ahomogeneous mixture. Attempts at forming crosslinked materials bydispersing the diacids in the epoxy have resulted in materials with poorproperties.

The reversible reaction of carboxylic acids with vinyl ether compoundsleads to liquid, low viscosity materials, i.e., the carboxylic acids canbe “blocked” via reactions with vinyl ether compounds. In the presenceof the proper catalyst, the vinyl group can “deblock” from thecarboxylic acid group and allow the acid to react with an epoxy group.See Nakane et al., Prog. Org. Coat. 31:113-120 (1997); Yamamoto et al.,Prog. Org. Coat. 40:267-273 (2000), the disclosures of which areincorporated herein by reference. The blocking vinyl ether group canalso be removed thermally.

SUMMARY OF THE INVENTION

In one embodiment, the invention relates to liquid vinyl-blockedbio-based polyfunctional carboxylic acids formed by the reaction of atleast one bio-based polyfunctional carboxylic acid with at least onevinyl ether compound.

In another embodiment, the invention relates to a homogeneous mixture ofthe liquid vinyl-blocked bio-based polyfunctional carboxylic acids ofthe invention mixed with at least one polyfunctional vegetable oil-basedepoxy resin, such as, for example, epoxidized vegetable oil sucroseester resin. Upon curing the homogeneous mixture at elevatedtemperature, thermoset coatings are formed which have excellenthardness, solvent resistance, adhesion, and flexibility.

In another embodiment, the invention relates to a curable coatingcomposition comprising at least one vinyl-blocked bio-basedpolyfunctional carboxylic acid and at least one polyfunctional vegetableoil-based epoxy resin. In another embodiment, the curable coatingcomposition of the invention may be coated onto a substrate and curedusing techniques known in the art. The substrate can be any commonsubstrate such as paper, polyester films such as polyethylene andpolypropylene, metals such as aluminum and steel, glass, urethaneelastomers, primed (painted) substrates, and the like. The curablecoating composition of the invention may be cured thermally.

In another embodiment, the invention relates to a method of making acurable coating composition of the invention comprising the step ofmixing at least one vinyl-blocked bio-based polyfunctional carboxylicacid with at least one polyfunctional vegetable oil-based epoxy resin.

In another embodiment, the invention relates to thermoset coatingsformed from the curable coating compositions of the invention.

In another embodiment, the invention relates to an article ofmanufacture comprising a thermoset coating of the invention and a methodof making such article.

Other features, objects, and advantages of the invention are apparent inthe detailed description that follows. It should be understood, however,that the detailed description, while indicating preferred embodiments ofthe invention, are given by way of illustration only, not limitation.Various changes and modifications within the scope of the invention willbecome apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts an exemplary epoxidation of a sucrose fatty acid ester.

FIG. 2 depicts the thermogravimetric analysis of cured coatings madeusing epoxidized sucrose soyate and azeleic acid (AzA) blocked bydifferent vinyl ether compounds.

FIG. 3 depicts the thermogravimetric analysis of cured coatings madeusing epoxidized sucrose soyate and succinic acid (SuA) blocked bydifferent vinyl ether compounds.

FIG. 4 depicts the thermogravimetric analysis of cured coatings madeusing epoxidized sucrose soyate and citric acid (CiA) blocked bydifferent vinyl ether compounds and furan dicarboxylic acid (FDCA)blocked by isobutyl vinyl ether (IBVE).

FIG. 5 depicts the thermogravimetric analysis of cured coatings madeusing epoxidized sucrose soyate and ethyl vinyl ether (EVE) blockedacids (succinic (SuA), adipic (AdA), glutaric (GlA), pimelic (PiA),subaric (SbA), azeleic (AzA), and sebacic (SeA)).

DESCRIPTION OF THE INVENTION Terminology and Definitions

Unless otherwise indicated, the invention is not limited to specificreactants, substituents, catalysts, catalyst compositions, resincompositions, reaction conditions, or the like, as such may vary. It isalso to be understood that the terminology used herein is for thepurpose of describing particular embodiments only and is not to beinterpreted as being limiting.

As used in the specification and the appended claims, the singular forms“a,” “an,” and “the” include plural referents unless the context clearlydictates otherwise. Thus, for example, reference to “a vinyl ethercompound” includes a single vinyl ether compound as well as acombination or mixture of two or more vinyl ether compounds, referenceto “a carboxylic acid” encompasses a single carboxylic acid as well astwo or more carboxylic acids, and the like.

As used in the specification and the appended claims, the terms “forexample,” “for instance,” “such as,” or “including” are meant tointroduce examples that further clarify more general subject matter.Unless otherwise specified, these examples are provided only as an aidfor understanding the invention, and are not meant to be limiting in anyfashion.

In this specification and the claims that follow, “optional” or“optionally” means that the subsequently described circumstance may ormay not occur, so that the description includes instances where thecircumstance occurs and instances where it does not. For example, thephrase “optionally substituted” means that a non-hydrogen substituentmay or may not be present on a given atom, and, thus, the descriptionincludes structures wherein a non-hydrogen substituent is present andstructures wherein a non-hydrogen substituent is not present.

Vinyl-Blocked Bio-Based Polyfunctional Carboxylic Acids

The invention relates to vinyl-blocked bio-based polyfunctionalcarboxylic acids comprising the reaction product of at least onebio-based polyfunctional carboxylic acid and at least one vinyl ethercompound. The vinyl-blocked bio-based polyfunctional carboxylic acidsare liquid at room temperature.

As used herein, a “bio-based polyfunctional carboxylic acid” means abio-based acid comprising at least two carboxylic acid groups. Forexample, the bio-based polyfunctional carboxylic acid may be selectedfrom dicarboxylic acids, tricarboxylic acids, or mixtures thereof. Thedicarboxylic acids and tricarboxylic acids may be saturated orethylenically unsaturated, optionally substituted by one or moresubstituents, and aromatic or non-aromatic. Unsaturation and/orsubstitution may occur in one or more positions anywhere on the alkylchains of the dicarboxylic acids and tricarboxylic acids.

For example, the bio-based polyfunctional carboxylic acid may be asaturated dicarboxylic acid having the following general structure:HOOC—(CH₂)_(n)—COOH. In one embodiment, “n” may be an integer rangingfrom 0 to 22, preferably 2 to 16, more preferably 6 to 10. For example,the saturated dicarboxylic acid includes, but is not limited to, oxalicacid (n=0), malonic acid (n=1), succinic acid (n=2), glutaric acid(n=3), adipic acid (n=4), pimelic acid (n=5), suberic acid (n=6),azelaic acid (n=7), sebacic acid (n=8), undecanedioic acid (n=9),dodecanedioic acid (n=10), tridecanedioic acid (n=11), tetradecanedioicacid (n=12), pentadecanedioic acid (n=13), hexadecanedioic acid (n=14),heptadecanedioic acid (n=15), octadecanedioic acid (n=16),nonadecanedioic acid (n=17), icosanedioic acid (n=18), henicosanedioicacid (n=19), docosanedioic acid (n=20), tricosanedioic acid (n=21), andtetracosanedioic acid (n=22).

In another embodiment, the saturated dicarboxylic acid may besubstituted by, for example, hydroxyl groups, as in tartaric acid, forexample.

In another embodiment, the bio-based polyfunctional carboxylic acid maybe an ethylenically unsaturated dicarboxylic acid selected from, forexample, maleic acid, fumaric acid, glutanoic acid, traumatic acid, andmuconic acid.

In one embodiment, the bio-based polyfunctional carboxylic acid may beselected from saturated and ethylenically unsaturated tricarboxylicacids, including, not limited to, citric acid, isocitric acid,homoisocitric acid, aconitic acid, propane-1,2,3-tricarboxylic acid,3-carboxy-cis,cis-muconic acid, and homoaconitic acid.

In a further embodiment, the bio-based polyfunctional carboxylic acidmay be selected from aromatic and non-aromatic dicarboxylic acids andtricarboxylic acids, including, but not limited to, (ortho-)phthalicacid, isophthalic acid, terephthalic acid, hemimellitic acid,trimellitic acid, trimesic acid, and 2,5-furandicarboxylic acid (FDCA).

The vinyl ether compounds may be linear, branched, or cyclic, andoptionally substituted. For example, the vinyl ether compounds may havethe following general structure:

wherein R may be a liner, branched, or cyclic C₁-C₁₈-alkyl group. Forexample, linear vinyl ether compounds include, but are not limited to,methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinylether, pentyl vinyl ether, hexyl vinyl ether, heptyl vinyl ether, octylvinyl ether, nonyl vinyl ether, decyl vinyl ether, undecyl vinyl ether,dodecyl vinyl ether, tridecyl vinyl ether, tetradecyl vinyl ether,pentadecyl vinyl ether, hexadecyl vinyl ether, heptyl vinyl ether, andoctadecyl vinyl ether. Branched vinyl ether compounds include, but arenot limited to, isopropyl vinyl ether, isobutyl vinyl ether, sec-butylvinyl ether, tert-butyl vinyl ether, and 2-ethyl hexyl vinyl ether.Cyclic vinyl ether compounds include, but are not limited to, cyclohexylvinyl ether. Substituted vinyl ether compounds include, but are notlimited to, hydroxybutyl vinyl ether.

Structures of exemplary vinyl-blocked bio-based polyfunctionalcarboxylic acids of the invention and their corresponding startingbio-based polyfunctional carboxylic acids and vinyl ether compounds areshown below in Table 3.

TABLE 3 Structures of exemplary vinyl-blocked bio-based polyfunctionalcarboxylic acids Bio-based polyfunctional carboxylic acids/vinyl ethercompounds Vinyl-blocked bio-based polyfunctional carboxylic acids

The vinyl-blocked bio-based polyfunctional carboxylic acids may besynthesized by a variety of methods. In one embodiment, thevinyl-blocked bio-based polyfunctional carboxylic acids are synthesizedby reacting the at least one bio-based polyfunctional carboxylic acidwith the at least one vinyl ether compound, at least one optionalcatalyst, and at least one optional solvent. In one embodiment, themolar ratio of vinyl groups in the at least one vinyl ether compound andcarboxylic groups in the at least one bio-based polyfunctionalcarboxylic acid used for the synthesis of the vinyl-blocked bio-basedpolyfunctional carboxylic acids may range from 1.0:1.0 to 10:1, morepreferably 4.0:1 to 6.0:1.0. Preferably, a stoichiometric excess ofmoles of vinyl ether groups relative to the carboxylic acid groups isused.

In one embodiment, the optional catalyst may be selected from phosphoricacid, hydrochloric acid, sulfuric acid, and the like. In a furtherembodiment, the optional catalyst may be present in an amount rangingfrom about 0.01% to about 5.0% by wt., preferably about 0.5% to about2.0% by wt., even more preferably about 0.1% to about 1.0% by wt., ofthe total reaction mixture.

In one embodiment, the optional solvent may be selected from benzene,toluene, xylene, heptane, hexane, and the like. In a further embodiment,the optional solvent may be present in an amount ranging from about 0.1%to about 50.0% by wt., preferably about 0.5% to about 15.0% by wt., evenmore preferably about 1.0% to about 2.0% by wt., of the total reactionmixture. Solvents may be used during the synthesis to reduce viscosityand facilitate the synthesis reaction.

After reacting, the optional catalyst may be removed using a base, suchas, for example, potassium hydroxide, in water via liquid-liquidextraction. Excess vinyl ether may be removed using known methods in theart, for example, rotary evaporation.

In one embodiment, the reaction to make the vinyl-blocked bio-basedpolyfunctional carboxylic acids of the invention may be carried out attemperatures dependent on the vinyl ether compound used. For example, areaction temperature of about 30° C. may be used for ethyl vinyl ether,about 70° C. may be used for propyl vinyl ether, and about 80° C. may beused for butyl or isobutyl vinyl ether. In one embodiment, the reactiontemperature may range from about 25° C. to about 100° C., morepreferably, from about 30° C. to about 90° C., even more preferably,from about 50° C. to about 70° C.

Curable Coating Compositions Comprising Vinyl-Blocked Bio-BasedPolyfunctional Acids and Polyfunctional Vegetable Oil-Based EpoxidizedResins

The invention also relates to curable coating compositions comprisingthe vinyl-blocked bio-based polyfunctional carboxylic acids describedabove and polyfunctional vegetable oil-based epoxidized resins.

The polyfunctional vegetable oil-based epoxy resins include, but are notlimited to, epoxidized vegetable oils, vegetable oil-based epoxy resins,and mixtures thereof. “Polyfunctional” as used herein in the phrase“polyfunctional vegetable oil-based epoxy resin” means the presence oftwo or more epoxide groups. Polyfunctional vegetable oil-based epoxyresins that may be used in the invention may be prepared in the mannerdisclosed in WO 2011/097484, the disclosure of which is incorporated byreference. For example, polyfunctional vegetable oil-based epoxy resinsare prepared from the epoxidation of vegetable oil fatty acid esters ofpolyols having >4 hydroxyl groups/molecule. Polyol esters of fatty acids(PEFA's) containing four or more vegetable oil fatty acid moieties permolecule can be synthesized by the reaction of polyols with 4 or morehydroxyl groups per molecule with either a mixture of fatty acids oresters of fatty acids with a low molecular weight alcohol, as is knownin the art. The former method is direct esterification while the lattermethod is transesterification. A catalyst may be used in the synthesisof these compounds. As shown in FIG. 1 with sucrose, as an exemplarypolyol to be used in the invention, esterified with a vegetable oilfatty acid, epoxide groups may then be introduced by oxidation of thevinyl groups in the vegetable oil fatty acid to form epoxidized polyolesters of fatty acids (EPEFA's). The epoxidation may be carried outusing reactions known in the art for the oxidation of vinyl groups within situ epoxidation with peroxyacid being a preferred method.

Polyols having at least 4 hydroxyl groups per molecule suitable for theprocess include, but are not limited to, pentaerythritol,di-trimethylolpropane, di-pentaerythritol, tri-pentaerythritol, sucrose,glucose, mannose, fructose, galactose, raffinose, and the like.Polymeric polyols can also be used including, for example, copolymers ofstyrene and allyl alcohol, hyperbranched polyols such as polyglycidoland poly(dimethylpropionic acid), and the like. Exemplary polyols areshown below in Scheme 3 with the number of hydroxyl groups indicated by(f). Comparing sucrose to glycerol, there are a number of advantages forthe use of a polyol having more than 4 hydroxyl groups/moleculeincluding, but not limited to, a higher number of fatty acids/molecule;a higher number of unsaturations/molecule; when epoxidized, a highernumber of oxiranes/molecule; and when crosslinked in a coating, highercrosslink density.

The degree of esterification may be varied. The polyol may be fullyesterified, where substantially all of the hydroxyl groups have beenesterified with the fatty acid, or it may be partially esterified, whereonly a fraction of the available hydroxyl groups have been esterified.It is understood in the art that some residual hydroxyl groups mayremain even when full esterification is desired. In some applications,residual hydroxyl groups may provide benefits to the resin. Similarly,the degree of epoxidation may be varied from substantially all to afraction of the available double bonds. The variation in the degree ofesterification and/or epoxidation permits one of ordinary skill toselect the amount of reactivity in the resin, both for the epoxidizedresins and their derivatives.

The hydroxyl groups on the polyols can be either completely reacted oronly partially reacted with fatty acid moieties. Any ethylenicallyunsaturated fatty acid may be used to prepare a polyol ester of fattyacids to be used in the invention, with polyethylenically unsaturatedfatty acids, those with more than one double bond in the fatty acidchain, being preferred. The Omega 3, Omega 6, and Omega 9 fatty acids,where the double bonds are interrupted by methylene groups, and the seedand vegetable oils containing them may be used to prepare polyol esterof fatty acids to be used in the invention. Mixtures of fatty acids andof vegetable or seed oils, plant oils, may be used in the invention. Theplant oils, as indicated above, contain mixtures of fatty acids withethylenically unsaturated and saturated fatty acids possibly presentdepending on the type of oil. Examples of oils which may be used in theinvention include, but are not limited to, corn oil, castor oil, soybeanoil, safflower oil, sunflower oil, linseed oil, tall oil fatty acid,tung oil, vernonia oil, and mixtures thereof. As discussed above, thepolyol fatty acid ester may be prepared by direct esterification of thepolyol or by transesterification as is known in the art. The doublebonds on the fatty acid moieties may be converted into epoxy groupsusing known oxidation chemistry yielding polyfunctional epoxy resins(EPEFA's)—epoxidized polyol esters of fatty acids. Table 4 lists thedouble bond functionality of some representative fatty acid esters(=/FA) based upon the number of esterified hydroxyl groups (f).

TABLE 4 Double Bond Functionality of Fatty Acids in Selected OilsFunctionality of = for FA esters having the indicated FA functionalityOil Avg. = /FA f = 3 f = 4 f = 6 f = 8 Soybean 1.54 4.62 6.16 9.24 12.32Safflower 1.66 4.98 6.64 9.96 13.28 Sunflower 1.39 4.17 5.56 8.34 11.12Linseed 2.10 6.30 8.40 12.60 16.80 Tall Oil 1.37 4.11 5.48 8.22 10.96Fatty Acid

The epoxidation of sucrose esters of ethylenically unsaturated vegetableoil fatty acids results in unique bio-based resins having a highconcentration of epoxy groups. As has been seen, functionalities of 8 to15 epoxide groups per molecule may be achieved, depending on thecomposition of the fatty acid used and the degree of substitution of thefatty acids on the sucrose moiety. This is substantially higher thanwhat can be achieved through epoxidation of triglycerides which rangefrom about 4 for epoxidized soybean oil up to 6 for epoxidized linseedoil.

The high epoxide functionality of these resins coupled with the rigidityof a polyol having at least 4 hydroxyl groups per molecule, such assucrose, has significant implications for the use of these polyols andtheir derivatives in curable coating compositions of the invention. Withthe epoxidized polyol esters of fatty acids (EPEFA's), crosslinkedmaterials having an outstanding combination of properties can beachieved.

Preferably, the polyfunctional vegetable oil-based epoxidized resin isselected from epoxidized sucrose soyate (ESS). As discussed above, fattyacids from soybean oil can be used to form esters with sucrose. Sucrosesoyate (SS) has many positive properties that make it an ideal startingpoint for bio-based coatings, including that it is polyfunctional, haslow viscosity (300-400 cP) with 100% solids, is 100% bio-based, and iscommercially available. Sucrose, soybean oil, and sucrose soyate havethe following structures:

In contrast to SS, epoxidized sucrose soyate (ESS) is more versatile.Many types of coatings can be formed from ESS. Also, ESS has manybeneficial properties, including 12 epoxy groups per molecule (epoxyequivalent weight of 270 g eq⁻¹), low viscosity (5,000 cP), 100%bio-based, easily synthesized, and is a clear and colorless resin. ESScan be synthesized in the manner disclosed in Pan et al., GreenChemistry 13:965-975 (2011), the disclosure of which is incorporatedherein by reference. See also Scheme 4 below.

The curable coating compositions comprising the vinyl-blocked bio-basedpolyfunctional carboxylic acids and the polyfunctional vegetableoil-based epoxidized resins can be prepared by a variety of methods. Inone embodiment, this method comprises combining the vinyl-blockedbio-based polyfunctional carboxylic acids described above with thepolyfunctional vegetable oil-based epoxidized resins to make curablecoating compositions of the invention. As a non-limiting example, thecurable coating compositions can be prepared by combining thevinyl-blocked bio-based polyfunctional carboxylic acids, describedabove, and the polyfunctional vegetable oil-based epoxidized resins inthe presence of at least one optional solvent, such as t-butyl acetate(TBA), methyl n-amyl ketone (MAK), ethyl 3-ethoxyproprionate (EEP), andat least one optional catalyst, such as dibutyltindilaurate (DBTDL).

In one embodiment, for the synthesis of the curable coating compositionsof the invention, a stoichiometric equivalent amount of epoxide andblocked acid groups may be used. In another embodiment, the ratio ofepoxy equivalents in the polyfunctional vegetable oil-based epoxidizedresin to carboxylic equivalents in the vinyl-blocked bio-basedpolyfunctional carboxylic acids can be varied in order to vary thecrosslink density and the properties of the curable coating composition.

The invention also relates to the use of a curable coating compositionwhich may be coated onto a substrate and cured. The substrate can be anycommon substrate such as paper, polyester films such as polyethylene andpolypropylene, metals such as aluminum and steel, glass, urethaneelastomers, primed (painted) substrates, and the like. The inventionalso provides methods for coating such substrates by applying thecurable coating composition to the substrate. The coating may be appliedby methods know in the art such as drawdown, conventional air-atomizedspray, airless spray, roller, brush. The curable coating composition ofthe invention may be cured thermally. Upon curing at elevatedtemperature, thermoset coating compositions of the invention haveexcellent hardness, solvent resistance, adhesion, and flexibility. Inanother embodiment of the invention, the invention relates to an articleof manufacture comprising a thermoset coating composition of theinvention.

A curable coating composition according to the invention may comprise apigment (organic or inorganic) and/or other additives and fillers knownin the art. For example a curable coating composition of the inventionmay further contain coating additives. Such coating additives include,but are not limited to, one or more leveling, rheology, and flow controlagents such as silicones, fluorocarbons or cellulosics; extenders;reactive coalescing aids such as those described in U.S. Pat. No.5,349,026, the disclosure of which is incorporated herein by reference;plasticizers; flatting agents; pigment wetting and dispersing agents andsurfactants; ultraviolet (UV) absorbers; UV light stabilizers; tintingpigments; colorants; defoaming and antifoaming agents; anti-settling,anti-sag and bodying agents; anti-skinning agents; anti-flooding andanti-floating agents; biocides, fungicides and mildewcides; corrosioninhibitors; thickening agents; or coalescing agents. Specific examplesof such additives can be found in Raw Materials Index, published by theNational Paint & Coatings Association, 1500 Rhode Island Avenue, N.W.,Washington, D.C. 20005. Further examples of such additives may be foundin U.S. Pat. No. 5,371,148, incorporated herein by reference.

Examples of flatting agents include, but are not limited to, syntheticsilica, available from the Davison Chemical Division of W. R. Grace &Company as SYLOID®; polypropylene, available from Hercules Inc., asHERCOFLAT®; synthetic silicate, available from J. M. Huber Corporation,as ZEOLEX®.

Examples of viscosity, suspension, and flow control agents include, butare not limited to, polyaminoamide phosphate, high molecular weightcarboxylic acid salts of polyamine amides, and alkylene amine salts ofan unsaturated fatty acid, all available from BYK Chemie U.S.A. as ANTITERRA®. Further examples include, but are not limited to, polysiloxanecopolymers, polyacrylate solution, cellulose esters, hydroxyethylcellulose, hydroxypropyl cellulose, polyamide wax, polyolefin wax,hydroxypropyl methyl cellulose, polyethylene oxide, and the like.

Solvents may also be added to the curable coating compositions in orderto reduce the viscosity. Hydrocarbon, ester, ketone, ether, ether-ester,alcohol, or ether-alcohol type solvents may be used individually or inmixtures. Examples of solvents can include, but are not limited tobenzene, toluene, xylene, aromatic 100, aromatic 150, acetone,methylethyl ketone, methyl amyl ketone, butyl acetate, t-butyl acetate,tetrahydrofuran, diethyl ether, ethylethoxy propionate, isopropanol,butanol, butoxyethanol, and so on.

EXAMPLES Example 1

Synthesis of blocked-azelaic acid compounds (Table 5). In a 50-mL singleneck round bottom flask, azelaic acid (5.00 g, 0.0266 mol) was combinedwith 4 molar equivalents (0.106 mol) of the appropriate vinyl ethercompound (7.66 g of ethyl vinyl ether, 9.15 g of propyl vinyl ether, or10.64 g of butyl or isobutyl vinyl ether). To this mixture, solidphosphoric acid (0.017 g, 0.177 mmol) was added. The mixture was stirredfor 5 hours at a temperature dependent on the vinyl ether compound used(30° C. for ethyl vinyl ether, 70° C. for propyl vinyl ether, or 80° C.for butyl or isobutyl vinyl ether). After the reaction mixture cooled toroom temperature, it was transferred to a 125-mL separatory funnel,where 40 mL of 0.05 M KOH was added. The funnel was capped and shaken toextract the phosphoric acid. The organic layer was isolated, and rotaryevaporation was used to remove the excess vinyl ether. Blocked-azelaicacid compounds were recovered in 84-94% yield. Example ¹H NMR data forpropyl vinyl ether blocked azelaic acid (CDCl₃, δ, ppm): 0.81 (triplet,6H, CH₃), 1.234 (singlet, 6H, O2C—CH2-CH2-CH₂-CH₂—CH₂—CH2-CH2-CO2),1.274 and 1.287 (singlet, 6H, O—CH(CH₃)—O), 1.49 (multiplet, 8H,O2C—CH2-CH₂ and O—CH2-CH₂—CH3), 2.21 (triplet, 4H, O2C—CH₂), 3.49(quartet, 4H, O—CH₂—CH2-CH3), 5.82 and 5.83 (quartet, 2H, O—CH(CH3)-O).A small amount of single blocked molecules is present, as evident bysome peak splitting and a small carboxylic acid peak present in the NMR.

Example 2

Synthesis of blocked-succinic acid compounds (Table 5). The procedureused for blocking azelaic acid compounds was used for their succinicacid equivalents, using 5.00 g succinic acid and the properly adjustedamounts of vinyl ether and phosphoric acid. Example ¹H NMR data forpropyl vinyl ether blocked succinic acid (CDCl₃, δ, ppm): 0.83 (triplet,6H, —CH₃), 1.30 (multiplet, 4H, O—CH(CH₂)—O), 1.50 (quartet, 4H,O—CH2-CH₂—CH3), 2.56 (triplet, 4H, O2C—CH₂—CH₂—CO2), 3.33 (quartet, 4H,O—CH₂—CH2-CH3), 5.86 and 5.87 (s, 2H, O—CH(CH2)-O). The presence ofother peaks suggests that the product is 3:1 mixture of two blockedcarboxylic acids per molecule to one blocked carboxylic acid permolecule.

Example 3

Synthesis of blocked-citric acid compounds (Table 5). In a 50-mL singleneck round bottom flask, citric acid (5.00 g, 0.0260 mol) was combinedwith 6 molar equivalents (0.156 mol) of the appropriate vinyl ethercompound (13.45 g of propyl vinyl ether or 15.64 g of butyl or isobutylvinyl ether). To this mixture, solid phosphoric acid (0.026 g, 0.260mmol) was added. The mixture was stirred for 18 hours using the sametemperatures used for the block-azelaic acid synthesis. The phosphoricacid was extracted using 40 mL of 0.05 M KOH, and the excess vinyl etherwas removed via rotary evaporation. Blocked-citric acid compounds wererecovered in 84-94% yield.

Example 4

Synthesis of isobutyl vinyl ether blocked 2,5-furandicarboxylic acid(Table 5). In a 50-mL single neck round bottom flask,2,5-furandicarboxylic acid (FDCA; 5.00 g, 0.0320 mol) was combined withisobutyl vinyl ether (IBVE; 12.83 g, 0.128 mol) and solid phosphoricacid (0.021 g, 0.214 mmol). The mixture was stirred for 18 hours at 80°C. The phosphoric acid was extracted using 40 mL of 0.05 M KOH. Theorganic layer was filtered using a Buchner funnel, and the excessisobutyl vinyl ether was removed from the filtered liquid via rotaryevaporation. This resulted in 6.40 g of IBVE-FDCA (56% yield) beingrecovered, along with the recovery of 1.76 g of unreacted FDCA (80% ofthe unreacted starting material).

TABLE 5 Structure of vinyl ether blocked acids produced Blocked AcidName Abbreviation Structure Ethyl vinyl ether blocked succinic acidEVE-SuA

Propyl vinyl ether blocked succinic acid PVE-SuA

Butyl vinyl ether blocked succinic acid BVE-SuA

Isobutyl vinyl ether blocked succinic acid IBVE-SuA

Ethyl vinyl ether blocked azelaic acid EVE-AzA

Propyl vinyl ether blocked azelaic acid PVE-AzA

Butyl vinyl ether blocked azelaic acid BVE-AzA

Isobutyl vinyl ether blocked azelaic acid IBVE-AzA

Ethyl vinyl ether blocked citric acid EVE-CiA

Propyl vinyl ether blocked citric acid PVE-CiA

Butyl vinyl ether blocked citric acid BVE-CiA

Isobutyl vinyl ether blocked citric acid IBVE-CiA

Isobutyl vinyl ether blocked 2,5- furandicarboxylic acid IBVE-FDCA

Example 5

Coating formulation method. Coating formulations were made using a 1:1mole ratio of epoxide to acid and 5% 1,8-Diazabicyclo[5.4.0]undec-7-ene(DBU) by total weight. For example, epoxidized sucrose soyate (ESS, 5.00g, 0.0188 equivalents), ethyl vinyl ether blocked azelaic acid (EVE-AzA,3.12 g, 0.0188 equivalents), and DBU (0.41 g, 0.0027 equivalents) werecombined in a formulation cup. The mixture was hand stirred to obtain aconsistent solution.

Coating application and curing. A Gardco wet film applicator was used toapply a 4 mil thick layer of each formulation onto Bonderite 1000treated steel and glass substrates. The substrates were then placed inan oven preheated to 170° C., where they were allowed to cure for 4hours.

Measurement of coating properties. Dried film thickness was measured onthe steel panels using a Byko-test 8500 (Table 6). Konig hardness of thefilms was measured using a Byk Gardner pendulum hardness tester on thesteel panels (Table 6). Pencil hardness, crosshatch adhesion, MEK doublerubs, and reverse impact were measured for dried films on steel panels(Table 6). Thermogravimetric analysis was performed by removing a sampleof each coating from the glass substrate and was analyzed using a TAInstruments Q-Series 500 Thermogravimetric analyzer (Table 7). T_(10%)is the temperature at 10 percent weight loss. FIGS. 2-4 depict thethermogravimetric analysis of the cured coatings.

TABLE 6 Dry film properties of ESS and blocked acid thermosets preparedMEK Konig Pencil Crosshatch Double Reverse Blocked Acid Film ThicknessHardness Hardness Adhesion Rubs Impact EVE-Azelaic Acid 20.1 ± 8.0 μm96.3 ± 7.6 3H 5B 400+ >168 in · lb PVE-Azelaic Acid 23.1 ± 5.2 μm 49.7 ±1.5 3H 5B 400+ >168 in · lb BVE-Azelaic Acid 13.2 ± 5.4 μm 82.0 ± 4.4 3H5B 400+ >168 in · lb IBVE-Azelaic Acid 11.2 ± 3.4 μm 93.7 ± 4.2 2H 5B400+ >168 in · lb EVE-Succinic Acid 24.6 ± 11.8 μm  24.7 ± 7.5 3B 5B400+  160 in · lb PVE-Succinic Acid 28.4 ± 3.6 μm 20.3 ± 0.6 2B 5B400+ >168 in · lb BVE-Succinic Acid 33.7 ± 8.7 μm 18.7 ± 2.9 2B 5B400+ >168 in · lb IBVE-Succinic Acid 25.8 ± 5.1 μm 25.0 ± 1.0 2B 5B400+ >168 in · lb EVE-Citric Acid  104 ± 25 μm 56.3 ± 1.5 3H 0B 70   8in · lb PVE-Citric Acid 74.1 ± 50.9 μm  18.7 ± 0.6 3B 2B 50  20 in · lbBVE-Citric Acid 49.3 ± 28.4 μm  24.0 ± 1.0 <EE 3B 100   40 in · lbIBVE-Citric Acid 38.8 ± 20.5 μm  67.7 ± 3.2 HB 0B 100   40 in · lbIBVE-FDCA 52.9 ± 5.3 μm 55.7 ± 3.2 H 5B 380   140 in · lb

TABLE 7 Thermal stability of cured coating formulations, as determinedby TGA Blocked Acid T_(10%), ° C. EVE-Azelaic Acid 329 PVE-Azelaic Acid297 BVE-Azelaic Acid 319 IBVE-Azelaic Acid 311 EVE-Succinic Acid 313PVE-Succinic Acid 311 BVE-Succinic Acid 301 IBVE-Succinic Acid 311EVE-Citric Acid 312 PVE-Citric Acid 317 BVE-Citric Acid 328 IBVE-CitricAcid 312 IBVE-FDCA 304

Example 6

Synthesis of additional ethyl vinyl ether-blocked bio-basedpolyfunctional carboxylic acids, curable coatings containing the sameand epoxide sucrose soyate, and properties thereof. The procedures usedto synthesize the vinyl-blocked bio-based polyfunctional carboxylic acidcompounds above were used to make the following ethyl vinyl ether(EVE)-blocked bio-based polyfunctional carboxylic acids: EVE-succinicacid (EVE-SuA), EVE-glutaric acid (EVE-GlA), EVE-adipic acid (EVE-AdA),EVE-pimelic acid (EVE-PiA), EVE-suberic acid (EVE-SbA), EVE-azelaic acid(EVE-AzA), and EVE-sebacic acid (EVE-SeA). See Table 8. Coatingcompositions containing these vinyl-blocked bio-based polyfunctionalcarboxylic acid compounds and epoxide sucrose soyate (ESS) were made,applied, cured, and properties measured (Table 9) in the same manner asthe coating compositions above. FIG. 5 depicts the thermogravimetricanalysis of these cured coatings.

TABLE 8 Structure of ethyl vinyl ether blocked acids produced BlockedAcid Name Abbreviation Structure Ethyl vinyl ether blocked succinic acidEVE-SuA

Ethyl vinyl ether blocked glutaric acid EVE-GIA

Ethyl vinyl ether blocked adipic acid EVE-AdA

Ethyl vinyl ether blocked pimelic acid EVE-PiA

Ethyl vinyl ether blocked suberic acid EVE-SbA

Ethyl vinyl ether blocked azelaic acid EVE-AzA

Ethyl vinyl ether blocked sebacic acid EVE-SeA

TABLE 9 Dry film properties of ESS and ethyl vinyl ether blocked acidthermosets prepared MEK Konig Pencil Crosshatch Double Reverse BlockedAcid Film Thickness Hardness Hardness Adhesion Rubs Impact EVE-SuccinicAcid 24.6 ± 11.8 μm  25 3B 5B 400+ >168 in · lb EVE-Glutaric Acid 20.2 ±10.9 μm  27 2B 5B 400+ >168 in · lb EVE-Adipic Acid 21.9 ± 5.5 μm 157 B5B 400+ >168 in · lb EVE-Pimelic Acid 16.6 ± 1.7 μm 160 HB 5B 400+ >168in · lb EVE-Suberic Acid 29.5 ± 3.1 μm 135 H 5B 400+ >168 in · lbEVE-Azelaic Acid 15.3 ± 7.1 μm 170 3H 5B 400+ >168 in · lb EVE-SebacicAcid 25.8 ± 5.7 μm 115 HB 5B 400+ >168 in · lb

Conclusions

Azelaic acid, succinic acid, and FDCA have superior solvent resistance,adhesion, and flexibility. Higher hardness of azelaic acid compared tothe others suggests a higher crosslinked system is produced. The poorproperties of citric acid based coatings suggest a lower inter-ESScrosslinked network is formed.

1. A vinyl-blocked bio-based polyfunctional carboxylic acid, comprisingthe reaction product of: a) at least one bio-based polyfunctionalcarboxylic acid; and b) at least one vinyl ether compound.
 2. Thevinyl-blocked bio-based polyfunctional carboxylic acid of claim 1,wherein said at least one bio-based polyfunctional carboxylic acid isselected from dicarboxylic acids, tricarboxylic acids, or mixturesthereof.
 3. The vinyl-blocked bio-based polyfunctional carboxylic acidof claim 1, wherein said at least one bio-based polyfunctionalcarboxylic acid is saturated or ethylenically unsaturated.
 4. Thevinyl-blocked bio-based polyfunctional carboxylic acid of claim 1,wherein said at least one bio-based polyfunctional carboxylic acid isoptionally substituted.
 5. The vinyl-blocked bio-based polyfunctionalcarboxylic acid of claim 1, wherein said at least one bio-basedpolyfunctional carboxylic acid is aromatic or non-aromatic.
 6. Thevinyl-blocked bio-based polyfunctional carboxylic acid of claim 1,wherein said at least one bio-based polyfunctional carboxylic acid isselected from oxalic acid, succinic acid, glutaric acid, adipic acid,pimelic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid,citric acid, furan dicarboxylic acid, and tartaric acid.
 7. Thevinyl-blocked bio-based polyfunctional carboxylic acid of claim 1,wherein said at least one vinyl ether compound is linear, branched, orcyclic.
 8. The vinyl-blocked bio-based polyfunctional carboxylic acid ofclaim 1, wherein said at least one vinyl ether compound is selected fromethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, and isobutylvinyl ether.
 9. (canceled)
 10. The vinyl-blocked bio-basedpolyfunctional carboxylic acid of claim 1, wherein the molar ratio ofvinyl groups in said at least one vinyl ether compound and carboxylicgroups in said at least one bio-based polyfunctional carboxylic acidrange from 1.0:1.0 to 10:1.
 11. The vinyl-blocked bio-basedpolyfunctional carboxylic acid of claim 1, wherein said vinyl-blockedbio-based polyfunctional carboxylic acid is selected from one of thefollowing:


12. A curable coating composition comprising: a) at least onevinyl-blocked bio-based polyfunctional carboxylic acid compound of claim1; b) at least one polyfunctional vegetable oil-based epoxy resin; c) atleast one catalyst; d) optionally, at least one solvent, at least oneother additive, or mixture thereof; and e) optionally, at least onepigment.
 13. The curable coating composition of claim 12, wherein saidat least one polyfunctional vegetable oil-based epoxy resin is preparedby the epoxidation of at least one vegetable oil fatty acid ester of apolyol having more than four hydroxyl groups per molecule.
 14. Thecurable coating composition of claim 13, wherein said at least onevegetable oil fatty acid ester of a polyol is prepared by the reactionof at least one polyol with four or more hydroxyl groups per moleculewith a mixture of fatty acids or esters of fatty acids with a lowmolecular weight alcohol.
 15. The curable coating composition of claim14, wherein said polyol with four or more hydroxyl groups per moleculeis selected from pentaerythritol, di-trimethylolpropane,di-pentaerythritol, tri-pentaerythritol, sucrose, glucose, mannose,fructose, galactose, and raffinose.
 16. (canceled)
 17. The curablecoating composition of claim 14, wherein said fatty acids are selectedfrom ethylenically unsaturated fatty acids, saturated fatty acids, ormixtures thereof.
 18. (canceled)
 19. The curable coating composition ofclaim 13, wherein said at least one vegetable oil fatty acid ester of apolyol having more than four hydroxyl groups per molecule is sucrosesoyate.
 20. The curable coating composition of claim 12, wherein said atleast one polyfunctional vegetable oil-based epoxy resin is anepoxidized vegetable oil, vegetable oil-based epoxy resin, or mixturethereof.
 21. (canceled)
 22. (canceled)
 23. (canceled)
 24. An objectcoated with the curable coating composition of claim
 12. 25. A method ofmaking a vinyl-blocked bio-based polyfunctional carboxylic acid of claim1, comprising the step of reacting at least one bio-based polyfunctionalcarboxylic acid with at least one vinyl ether compound, at least oneoptional catalyst, and at least one optional solvent.
 26. (canceled) 27.(canceled)
 28. (canceled)
 29. (canceled)
 30. A method of making acurable coating composition of claim 12, comprising the step of mixingat least one vinyl-blocked bio-based polyfunctional carboxylic acidcompound with at least one polyfunctional vegetable oil-based epoxyresin.